Ahh, that's the answer I was looking for. I couldn't test it right away because I was not at work. But I just did and it works perfectly.
thanks for your help all of you. On Thu, Aug 28, 2008 at 7:45 AM, Vican, Justin E. <[EMAIL PROTECTED]> wrote: > Hi Louis, > When you pass the osg::Program* to the StateSet, the StateSet object holds > on to it as an osg::ref_ptr<osg::Program>. When you call removeAttribute, > that ref_ptr de-references the program. Because you are keeping a pointer to > the program and not a ref_ptr to the program, the reference count in the > osg::Program class goes to zero, and the osg::Program object is deleted by > the osg::ref_ptr class inside of the StateSet::removeAttribute method. > Therefore, after you call removeAttribute, the pointer that you have is > pointing to invalid memory ... the program has been deleted out from under > you. Use the osg::ref_ptr class, and the problem will be solved. I had the > exact same issue, and this solution resolved it. > -Justin > ________________________________ > From: [EMAIL PROTECTED] on behalf of Louis Bouchard > Sent: Thu 8/28/2008 12:07 AM > To: [EMAIL PROTECTED]; OpenSceneGraph Users > Subject: Re: [osg-users] Fwd: Strange stateset / shader problem > > it's a osg::Program*. The thing is, after the call to > removeAttribute(), the osg::Program* is still valid. The object has > not been deleted, and the pointer is certainly not null. I checked. > Unless something inside the osg::Program structure has been screwed > with. > > I don't see how ref_ptrs are necessary in that case. I understand why > they can be practical, like boost's shared_ptr, but hardly necessary > all the time. Their main use is to have objects automatically deleted > when the ref count hit 0, so you don't have to destro them manually, > right? > > Then, in my case, I certainly don't explicitely destroy the > osg::program, and in the source code for StateSet, the pointer is > removed form a std::vector<StateAttribute>, which I don't think > implies the destruction of the object referred to by the pointer. > > > On Wed, Aug 27, 2008 at 9:07 PM, Gordon Tomlinson > <[EMAIL PROTECTED]> wrote: >> >> I would guess it is a reference count issue if you want to add and remove >> and keep a reference counted object then you could call ::ref() on the >> object when you create it or use the preferred method of using a variable >> an >> osg::ref_ptr<object> to preserve the scope of the object >> >> __________________________________________________________ >> Gordon Tomlinson >> >> [EMAIL PROTECTED] >> IM: [EMAIL PROTECTED] >> www.vis-sim.com www.gordontomlinson.com >> __________________________________________________________ >> >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of Louis >> Bouchard >> Sent: Wednesday, August 27, 2008 5:52 PM >> To: [email protected] >> Subject: [osg-users] Fwd: Strange stateset / shader problem >> >> Hi, >> >> since we cannot turn off a shader program like this: >> >> setAttributeAndModes(shaderprogram, osg::StateAttribute::OFF) >> >> .. I tried the suggested method from this post >> (http://www.mail-archive.com/[EMAIL PROTECTED]/msg08493.html), >> and I simply removeAttribute(...) the shader from the stateset. This >> part works quite well. >> >> However, if I want to turn it back on again, >> setAttributeAndModes(shaderprogram, osg::StateAttribute::ON) produces >> a segmentation fault. I have no idea why. The shaderprogram pointer >> is still valid. I ran this through gdb and it was unhelpful. >> >> any ideas? >> >> thanks, >> >> Louis Bouchard >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
